*{margin:0;padding:0;box-sizing:border-box}
:root{--bg:#0a0a0f;--sidebar:#111116;--card:#1a1a24;--border:#ffffff0d;--text:#ededed;--muted:#71717a;--accent:#06b6d4;--accent2:#3b82f6;--danger:#ef4444}
body{font-family:'Inter',sans-serif;background:var(--bg);color:var(--text);height:100vh;overflow:hidden;-webkit-font-smoothing:antialiased}

/* LOGIN */
.login-screen{display:flex;align-items:center;justify-content:center;min-height:100vh;padding:20px;background:radial-gradient(ellipse at 50% 0%,rgba(6,182,212,.08),transparent 60%)}
.login-card{text-align:center;max-width:420px;width:100%;padding:48px 36px;background:rgba(255,255,255,.02);border:1px solid var(--border);border-radius:24px}
.login-logo{width:64px;height:64px;margin:0 auto 24px;background:linear-gradient(135deg,var(--accent),var(--accent2));border-radius:16px;display:flex;align-items:center;justify-content:center;font-size:28px;color:#fff}
.login-card h1{font-size:28px;font-weight:800;margin-bottom:8px;color:#fff}
.login-card h1 span{color:var(--accent)}
.login-card>p{color:var(--muted);font-size:14px;line-height:1.6;margin-bottom:32px}
.btn-google{display:inline-flex;align-items:center;gap:10px;padding:14px 32px;background:#fff;color:#333;font-weight:600;font-size:15px;border-radius:12px;text-decoration:none;transition:all .2s}
.btn-google:hover{transform:translateY(-2px);box-shadow:0 8px 25px rgba(255,255,255,.1)}
.login-footer{margin-top:24px;font-size:12px;color:var(--muted)}

/* APP LAYOUT */
.app{display:flex;height:100vh}

/* SIDEBAR */
.sidebar{width:280px;background:var(--sidebar);border-right:1px solid var(--border);display:flex;flex-direction:column;flex-shrink:0;transition:transform .3s}
.sidebar-header{padding:16px;border-bottom:1px solid var(--border)}
.btn-new{width:100%;padding:12px;background:rgba(255,255,255,.05);border:1px solid var(--border);border-radius:12px;color:#fff;font-size:14px;font-weight:500;cursor:pointer;display:flex;align-items:center;gap:8px;justify-content:center;transition:all .2s}
.btn-new:hover{background:rgba(255,255,255,.1)}
.sidebar-list{flex:1;overflow-y:auto;padding:8px}
.sidebar-list::-webkit-scrollbar{width:4px}
.sidebar-list::-webkit-scrollbar-thumb{background:#27272a;border-radius:4px}
.convo-item{padding:10px 12px;border-radius:10px;cursor:pointer;font-size:13px;color:var(--muted);white-space:nowrap;overflow:hidden;text-overflow:ellipsis;transition:all .15s;display:flex;align-items:center;justify-content:space-between;gap:8px}
.convo-item:hover{background:rgba(255,255,255,.05);color:#fff}
.convo-item.active{background:rgba(6,182,212,.1);color:#fff}
.convo-title{flex:1;overflow:hidden;text-overflow:ellipsis}
.convo-del{opacity:0;color:var(--danger);font-size:12px;cursor:pointer;padding:4px;transition:opacity .15s}
.convo-item:hover .convo-del{opacity:1}

/* SIDEBAR FOOTER */
.sidebar-footer{padding:12px 16px;border-top:1px solid var(--border)}
.token-bar{margin-bottom:12px}
.token-label{font-size:12px;color:var(--muted);margin-bottom:6px;display:flex;align-items:center;gap:6px}
.token-track{height:4px;background:rgba(255,255,255,.05);border-radius:4px;overflow:hidden}
.token-fill{height:100%;background:linear-gradient(90deg,var(--accent),var(--accent2));border-radius:4px;transition:width .4s ease}
.user-info{display:flex;align-items:center;gap:10px;padding:8px 0}
.avatar{width:32px;height:32px;border-radius:50%;border:2px solid var(--border)}
.user-name{flex:1;font-size:13px;font-weight:500;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.btn-logout{color:var(--muted);font-size:14px;transition:color .2s;text-decoration:none}
.btn-logout:hover{color:var(--danger)}

/* MAIN CHAT */
.chat-main{flex:1;display:flex;flex-direction:column;position:relative;min-width:0}
.btn-toggle{display:none;position:absolute;top:16px;left:16px;z-index:20;background:rgba(255,255,255,.05);border:1px solid var(--border);border-radius:10px;color:#fff;width:40px;height:40px;font-size:16px;cursor:pointer}

/* WELCOME */
.welcome{flex:1;display:flex;flex-direction:column;align-items:center;justify-content:center;padding:40px;text-align:center}
.welcome-icon{width:72px;height:72px;background:linear-gradient(135deg,var(--accent),var(--accent2));border-radius:20px;display:flex;align-items:center;justify-content:center;font-size:32px;color:#fff;margin-bottom:24px;animation:float 4s ease-in-out infinite}
@keyframes float{0%,100%{transform:translateY(0)}50%{transform:translateY(-8px)}}
.welcome h2{font-size:28px;font-weight:700;margin-bottom:8px}
.welcome p{color:var(--muted);font-size:16px;margin-bottom:32px}
.suggestions{display:flex;gap:12px;flex-wrap:wrap;justify-content:center}
.sug{padding:12px 20px;background:rgba(255,255,255,.03);border:1px solid var(--border);border-radius:14px;color:var(--muted);font-size:13px;cursor:pointer;display:flex;align-items:center;gap:8px;transition:all .2s}
.sug:hover{background:rgba(6,182,212,.08);color:#fff;border-color:rgba(6,182,212,.3)}

/* MESSAGES */
.messages{flex:1;overflow-y:auto;padding:24px 0;display:flex;flex-direction:column}
.messages::-webkit-scrollbar{width:6px}
.messages::-webkit-scrollbar-thumb{background:#27272a;border-radius:6px}
.msg{max-width:780px;width:100%;margin:0 auto;padding:16px 24px;display:flex;gap:16px;animation:fadeIn .3s ease}
@keyframes fadeIn{from{opacity:0;transform:translateY(8px)}to{opacity:1;transform:translateY(0)}}
.msg-avatar{width:32px;height:32px;border-radius:10px;flex-shrink:0;display:flex;align-items:center;justify-content:center;font-size:14px}
.msg-user .msg-avatar{background:rgba(255,255,255,.08);color:var(--muted)}
.msg-assistant .msg-avatar{background:linear-gradient(135deg,var(--accent),var(--accent2));color:#fff}
.msg-body{flex:1;min-width:0;line-height:1.7;font-size:15px}
.msg-body p{margin-bottom:8px}
.msg-body code{background:rgba(255,255,255,.08);padding:2px 6px;border-radius:4px;font-size:13px}
.msg-body pre{background:#111116;border:1px solid var(--border);border-radius:10px;padding:16px;overflow-x:auto;margin:12px 0;font-size:13px}
.msg-body pre code{background:none;padding:0}
.msg-body ul,.msg-body ol{margin:8px 0 8px 20px}
.msg-body li{margin-bottom:4px}
.msg-body h1,.msg-body h2,.msg-body h3{margin:16px 0 8px;font-weight:700}
.msg-body h1{font-size:20px}
.msg-body h2{font-size:18px}
.msg-body h3{font-size:16px}
.msg-body strong{color:#fff}
.msg-body a{color:var(--accent);text-decoration:underline}
.msg-body blockquote{border-left:3px solid var(--accent);padding-left:12px;color:var(--muted);margin:8px 0}

.typing-indicator{display:flex;gap:4px;padding:8px 0}
.typing-indicator span{width:8px;height:8px;background:var(--accent);border-radius:50%;animation:bounce 1.4s infinite}
.typing-indicator span:nth-child(2){animation-delay:.2s}
.typing-indicator span:nth-child(3){animation-delay:.4s}
@keyframes bounce{0%,60%,100%{transform:translateY(0)}30%{transform:translateY(-8px)}}

/* INPUT */
.input-area{padding:12px 24px 20px;max-width:780px;width:100%;margin:0 auto}
.input-wrap{display:flex;align-items:flex-end;background:rgba(255,255,255,.04);border:1px solid var(--border);border-radius:16px;padding:8px 8px 8px 16px;transition:border-color .2s}
.input-wrap:focus-within{border-color:rgba(6,182,212,.4)}
#msgInput{flex:1;background:none;border:none;color:#fff;font-size:15px;font-family:inherit;resize:none;outline:none;max-height:200px;line-height:1.5;padding:6px 0}
#msgInput::placeholder{color:var(--muted)}
#btnSend{width:36px;height:36px;border-radius:10px;background:linear-gradient(135deg,var(--accent),var(--accent2));border:none;color:#fff;font-size:14px;cursor:pointer;flex-shrink:0;transition:all .2s}
#btnSend:hover{transform:scale(1.05)}
#btnSend:disabled{opacity:.3;cursor:not-allowed}
.input-hint{text-align:center;font-size:11px;color:var(--muted);margin-top:8px}

/* LIMIT BANNER */
.limit-banner{max-width:780px;margin:0 auto;padding:16px 24px;background:rgba(239,68,68,.08);border:1px solid rgba(239,68,68,.2);border-radius:14px;color:#fca5a5;font-size:14px;text-align:center;display:none}

/* MOBILE */
@media(max-width:768px){
  .sidebar{position:fixed;z-index:30;height:100vh;transform:translateX(-100%)}
  .sidebar.open{transform:translateX(0)}
  .btn-toggle{display:flex;align-items:center;justify-content:center}
  .suggestions{flex-direction:column}
  .msg{padding:12px 16px}
  .input-area{padding:8px 12px 12px}
}